1. Field of the Invention
The present invention relates generally to a surgical device, and, in particular, to a resectoscope having electrically powered cutting and coagulating/vaporizing means for cutting, coagulating, and removing tissue from a patient during a surgical procedure.
2. Description of the Prior Art
A resectoscope is employed transurethrally to perform bladder and/or prostate surgery. This device generally contains an elongated section provided with an outer sheath made of stainless steel which is inserted into the urethra. This outer sheath prevents the urethra from contracting, while the working elements of the device are located within the sheath. These working elements are employed to cut, coagulate, vaporize and retrieve the target tissue.
Conventional resectoscopes are manually operated; a heated cutting/coagulating element, known as a diathermy wire loop, is extended manually beyond the end of the outer sheath to a position engaging the tissue to be cut. The cutting element is then energized through activation of a diathermy unit connected to the resectoscope, and at the same time the cutting element is manually retracted, slicing away a section of prostate or bladder tissue. The surgeon must view the surgical site through a telescopic system which is also contained within the working element. In addition, it is necessary to continuously irrigate the surgical site to keep the viewing area free of blood and tissue debris for the surgeon.
During typical prostate surgery, it is common to excise approximately 0.1 gram of tissue with each cutting stroke. Although the total weight of the tissue to be removed varies with the size of the prostate, it is quite common to remove anywhere from 20 to 60 grams of prostate tissue in a typical transurethral resection of the prostate. Thus, in a standard procedure, it is necessary to manually reciprocate the cutting element at least 200 times, which is quite time consuming and could possibly affect the morbidity of the operation result.
U.S. Pat. No. 4,657,018, which issued to Hakky, discloses a resectoscope capable of automatic operation; the surgeon can perform the prostate or bladder procedure either manually or automatically. This automatic/manual resectoscope uses a linear cutting approach, which has several inherent drawbacks. For example, the operating speed is limited, which reduces one of the advantages offered by this device, and certain areas of the prostate anatomy cannot be easily accessed by linear motion.
This problem is addressed in U.S. Pat. Nos. 4,955,882; 5,201,731; and 5,498,258, which all teach rotary techniques in cutting and retrieving resected prostate or bladder tissue. In addition, U.S. Pat. No. 5,498,258 teaches the use of TEFLON coated rotary blades which are heated by a laser to cut and coagulate prostate or bladder tissue.
In certain parts of the world a laser unit may not be readily available in the operating room; there is, however, a diathermy unit located in every operating room worldwide. It is possible to substitute this unit for a laser, and by combining diathermy with a rotary cutting mechanism a more efficient procedure can be performed, which will be reflected in the quicker recovery of the patient. The procedure can now be performed on an outpatient basis with minimal anesthesia.